Thermosensitive instrument



May 27, 1941. R. E. OLSON THERMOSENSITIVE INSTRUMENT Filed May 1'7, 1939INVENTOR. RAYMOND E. OLSON ATTQR Patented May 27, 1941 THERMOSENSITIVEINSTRUMENT Raymond E. Olson, Pittsford, N. Y., assignor to TaylorInstrument Companies, Rochester, N. Y.,

a corporation of New York Application May 17, 1939, Serial No. 274,239

4 Claims.

This invention relates to thermosensitive instruments.

In the manufacture of various products particularly rayon, it isnecessary to shred and mix the raw materials preferably at apredetermined temperature. Since the mentioned raw mate-'- rials, whichinclude cellulose, are relatively poor heat conductors, it is diiiicultto obtain an ac curate determination of the average temperatur thereof.Furthermore, the bulb and other sensing unit of a temperature indicatingor regulatin'g instrument used for this purpose, must be exposed to thematerial which is subjected to severe forces during the shreddingoperation.

In Patent No. 2,123,019 granted to Olson and Tate on July 5, 1938, thereis disclosed a thermosensitive instrument including a bulb or unit forsensing the temperature of the material being treated in arshredder.Thisbulb although it is effective in service, is expensive tomanufacture. The present invention has for its purpose an improvementinthe temperature unit disclosed in the mentioned patent whereby thereis provided a unit of simpler and less expensive construction but ofequal or superior durability with respect to that of the patentedarrangement.

The features of the invention will appear from I the detaileddescription and claims when taken with the drawing in which Fig. 1 is avertical longitudinal section taken through a shredder, together with atemperature indicating instrument, the bulb of which extends lengthwisein the receptacle: Fig. 2 is a vertical section taken substantially onthe line 2-4 of Fig. 1; Fig. 3

is an enlarged view partially in section of the tubuiar support for thebulb portion of the tube system secured thereto and also shows the meansfor attaching the support to the opposing walls of a receptacle; Fig. 4is a fragmentary view partially in section illustrating a modifiedarrangement for mounting the tubular support and is bulb in the walls ofa receptacle; Fig. 5 is a fragmentary view partially in section of amodicontain a circulating, cooling medium introduced from a circulatingsystem (not shown), which medium is controlled either manually orautomatically by means (not shown) to prevent any deviation intemperature which is indicated by the thermosensitive instrument R. Theinstruile'i arrangement of the bulb portion mounted on L the tubularsupport; Fig. 6 is an end view of Fig. i

ment herein illustrated is represented as being a temperature indicator,but it will be understood that it can be a combined indicator andcontrol ler, in which case the regulating portion the eof will controlthe flow of the circulating cooling medium.

Within the receptacle 6 there is provided a metal saddle ll having twotoothed surfaces l2 and I3 with which the blades M and i5 015 thecutters respectively cooperate. In accordance with the usual practice,these blades arearranged to rotate alternately by means (not shown),first in one direction and then after a predetermined interval in thereverse direction as indicated by the arrows.

The mentioned instrument R includes a metallic bulb it connected througha capillary tube ll to a Bourdon spring 3 constituting a tube systemwhich is filled with a thermosensitive medium (not shown). It will beunderstood that the free end of the Bourdon spring is connected by alink 19 to a pen arm 20 pivoted at 29 on the instrument frame. The lowerend of the pen arm carries a stylus in operative relation to a graduatedchart 22 which is arranged to be rotated by a suitable clock mechanism(not shown).

In order that the bulb l6 may be immersed in the cellulose or the likewithin the shredder and yet be supported in a manner to withstand thesevere stresses to which it is subjected, the bulb is arranged toembrace a support 23, such as by being helically wound thereon andwelded there to indicated at 32. This support is preferably tubular andis of a length to extend between and be mounted on two opposing walls ofthe shred-- der. is shown in Figs. 1 and 3, the left end-of the support23 is received in the recess of a socket 2 3 which is provided with aflange 25 adapted to be screwed or otherwise attached to a wall of theshredder. The other end of the support 23 is received in the collar 26having a flange 21 for attachment to the opposite wall of the shredder.This last-mentioned end of the tubular support 23 is preferably weldedto the collar 26 as indicated at 28. Thus the right-hand end of thesupport is rigidly fastened to the wall of the shredder, while the otherend of the support is free to move in the socket 14 thereby permittingthe expansion and contraction of this support in response to variationsin temperature to which it is exposed during use. The right hand end ofthe bulb portion ll .(Fig. 3) extends into the interior of the tubularsupport through an opening 30 therein. The junction of the capillarytube II with the bulb portion is preferably located within the support,the capillary tube emerging through a sleeve 3| received in a cap 33which closes the right hand end of the support.

While the dimensions of the bulb may vary within rather wide limits, thewall thickness thereof should be such as to resist collapsing under theseverepressures to which it is sub-- jected and yet the mass of metal inthe bulb should be as small as, possible, to permit prompt thermalresponse of the thermosensitive medium in the bulb. To this end a bulbhaving an external diameter of .250 inch and an internal diameter-of.110 inch has been found satisfactory. The length of the bulb should besuch that volume of the thermosensitive medium therein will develop apressure sufficient to actuate the instrument on relatively smallchanges in temperature. The helical arrangement of the bulb' on thesupport, provides an exceedingly durable construction and furtherinsures a large area of bulb exposure to the material being shredded.

The modified bulb unit shown in Fig. 4 differs from that shown in Figs.1, 2, and 3 in that each end of the tubular support 23a has weldedthereto a threaded sleeve 35. These sleeves are adapted to be receivedin alined openings in opposing walls of the shredder where clamping nutsengaging the outside walls of the shredder and the threaded collars,lock the tubular support in position. It will be understood that themounting of the bulb portion i5 is the same as that previouslydescribed.

The modified form of the invention shown in Fig. 5 diifers from thatshown in the foregoing figures in that the bulb portion ii of the tubesystem instead of being helically wound around the tubular support 23b,is arranged in zig-zag relation, that is, folded back and forth uponitself along the. principal axis of the tubular support. While twoarrangements have been disclosed for applying the bulb portion of thetube system to the tubular or other support, it will be understood thatvarious other bulb arrangements can be provided within the scope of thepresent invention.

The modified form of the invention illustrated in Figs. 7 and 8 issimilar to that illustrated in Figs. 1, 2 and 3. However, in thisinstance the bulb i6 is Joined to the capillary tube 11 at it outside ofthe support 23. From this junction the capillary tube extends throughthe bore in the collar 26. The flange 21 on this collar is provided witha recess 31 to receive the capillary tube. Thus the capillary tube IIcan extend upward along the inner wall of the receptacle 6, beingsuitably attached thereto.

I claim: 1. In a temperature responsive instrument including a bulbportion, a pressure responsive element and a capillary tubecommunicating stantially its entire length, means rigidly securing saidbulb portion to the exterior surface of said support, said bulb portionhaving a part extending through said opening into the interior of saidsupport, said capillary tube extending into one end of the support andcommunicating with said bulb within said support.

2. In a temperature responsive element including a bulb portion, apressure responsive element and a capillary tube communicating'with saidbulb portion and said element, a rigid cylindrical support adapted tohave its ends respectively secured to the opposing walls of a receptaclewith which the instrument is to be used, said bulb portion being ofsmaller diameter than said support and means rigidly securing said bulbportion in helical relation on .the exterior of said support throughoutsubstantially the entire length thereof.

3. In a temperature responsive instrument including a bulb portion, apressure responsive element and a capillary tube oommunicatins with saidbulb portion and said element, a rigid cylindrical support adapted tohave its ends respectively secured to the opposing walls of a receptaclewith which the instrument is to be used, said bulb portion being foldedback and forth on itself in parallel relation to the principal axis ofsaid support and means rigidly securing said bulb portion to saidsupport.

4. In a temperature responsive instrument including a bulb portion, apressure responsive element and a capillary tube communicating with saidbulb portion and said element, a rigid support adapted to have its endsrespectively secured to the opposing walls 0! a receptacle with whichthe instrument is to be used, said I support having an openingtherethrough near one end thereof, said bulb portion being of a smallerdiameter than that of the support and embracing the exterior of saidsupport throughout substantially its entire length, means rigidlysecuring said bulbportion to said support, said capillary tube having apart extending through said opening into the interior of said supportand thence through one end of the support for connection with saidpressure element.

RAYMOND E. OLSON.

responsive r

